How do you solve this i don't under stand

Asphere has a diameter of 10 in. what is the volume of the sphere?

Aefg - almn. find the ratio of aefg to almn. a)1: 4 b)1: 2 c)2.1 d)4: 1

Which questions would most a reader identify the author's purpose for writing? check all that apply. what type of text is this? what type of reviews did the book receive? how many copies of the book have been sold? what is the central idea? how does this text make one feel?